Axel g



A. G. BERGMAN.

TRENCH GUN.

APPLICATION man SEPT-10.1915.

latentedSept. 80, 1919.

] nuamiioz UNITED STATES PATENT OFFICE.

AXEL G. BERGMAN, OF JERSEY CITY, NEW JERSEY, ASSIGNOR 0F ONE-HALF 'roTHOMAS H. NEWKIRK, OF NEW YO K, 1v. Y.

THENCE-GUN.

Specification of Letters Patent. Patented Sept. 30, 1919.v

Application filed. September 10, 1915. Serial No. 49,879.

To all whom it may concern:

Be it known that I, AxEL G. BERGMAN, a subject of the King of Sweden,and a resident of Jersey City, in the county of Hudson and State of NewJersey, have invented certain new and useful Improvements inTrench-Guns, of which the following is a specification.

My invention relates to trench guns and more particularly to guns forthrowing.

bombs, grenades and similar devices.

In trench warfare special guns have been devised for throwing or hurlingbombs, grenades and similar devices, but explosive charges have not beenuniversally used for throwing the projectiles owing to disadvantages inusing such charges for these projectiles at various short ranges. Intrench warfare, projectiles in the nature of bombs and grenades are usedat comparatively short ranges and it has heretofore been diflicult toemploy explosive charges for the propelling force and to provide forvariations in the range of fire. V s

Under my present invention it is possible to use explosives for thepropellingforce and to alter the range of fire very easily and with thenecessary degree of accuracy. The change of the range of fire is notmade as heretofore, by altering the angle of the gun, but by modifyingthe action of the explosive charge upon the projectile. Thus, the rangeof fire may be altered within certain limits without altering the angleof the gun, so that once the gun is positioned it is seldom necessary tochange its angle. This is of considerable advantage in trench warfarebecause of the limited spacewhich the gunners usually have in whichtomanipulate the gun; It is also an advantage because the trench portthrough which the'gun is fired may be comparatively small. 7 7

Another advantage is, that an explosive may be used for the propellingforce and the range of fire may be varied and still the parabolic curvetraversed by the projectile will always be such as to permit theprojectile to clear the ordinary parapet and drop Within the trench.

Another advantage is that the propelling charges may consist of blankcartridges all.

having the same explosive charge and which may be factory loaded and therange may be varied by manipulating the gun to modify the action of theexplosive on the projectile.

- I provide means for varying the angle of the gun but this is onlynecessary for very wide variations in the range. V

In the drawings forming part of this application, i Figure l is a planview ofa gun embody- 111g my invention in one form,

F g. 2 is a side elevation thereof,

Flg. 3 is a sectional view, onthe line 3-3 of Fig. 4, Fig. 4 is asectional view on the line 44 of Fig. 3,

Fig. 5 is a sectional View on the line 5 7 of Fig. 4, and r 6 is a viewvery similar to Fig. 5 but with the parts in the position following discharge of the projectile.

I have" shown my invention embodied in very simple form having but fewparts. a i

The support 1 may be of any form, but herein I haveshowna standconsisting of the forwardly extending legs 2 and rearwardly extendinglegs 3 all fulcrumed upon trunnions 4: at the sides of the gun barrel 5.The barrel 5 may be of comparatively light weight because light chargesof ex plosive will usually serve the purpose of throwing projectiles intrench warfare. I have shown a barrel 5 consisting of a metal tube orcylinder having a breech 6 threaded thereon. the projectiles may fitloosely therein for all practical purposes. I prefer to load the gun byinserting the projectile, which maybe a bomb, grenade or similar device,into the The barrel need not be rifled as muzzle and allowing it toslide down in the I barrel.

a The barrel may be swung on the trunnions 4k in relation to its support1, and if the barrel-is arranged as here shown it will tend to swingdown at the rear owing to the greater weight being arranged behind thetrunnions. A yoke 7 connected between the legs 3 carries an adjustingscrew 8 which is operated by the wheel 9, and the rear end of the'barrel5 rests on the end of this adjusting screw. By turning this screw theelevation of the barrel maybe altered.

There is a sleeve 10 on the barrel, to which a segmental link 11, isfulcrumed at 12 and this'link has a scale 13 to indicate various anglesof inclination. An arm 14 pivoted to Y rounding the link 11 and adaptedto beclamped at any position. thereon by a thumb screw 19. To regulatethe elevation of the barrel 5 to a certain angle the arm 14 is clampedto thelink 11 at the point where the desired angle is indicated on thescale 13. The wheel 9 is then turned to the right or left to elevate ordepress the barrel, as the case may be, until the spirit level 17 indicates that the arm 14 is level. This will indicate that the barrel iselevated-to the degree indicated on the scale.

For discharging the projectile I prefer to use a blank cartridge such aswould be used in a rifle. For instance, a blank cartridge of the type ofa 45-70 rifle cartridge will sufiice to send atwo pound grenade or bomb150 meters.

I have shown the breech 6 provided with a bore 20 to receive such acartridge from the rear, with an enlargement 21 to receive the rim orflange of the cartridge. It is to be understood that this arrangement isnot imperative as the form of the device may be changed to adapt it forother forms of explosive charges.

There is shown a breech block 22 which constitutes part of a yoke, thearms 23, 24 0f the yoke being fulcrumed on the trunnions 25 at oppositesides of the breech.

The rear end of the breech 6 is preferably curved on an arc concentricwith the trunnions 25 and the breech block 22 is preferably concaved at26 on a similar are to make these parts close fitting. I i

There is a. tubular casing 27 threaded to the breech block 22 and itincloses a firing pin 28 which moves through an opening 29 in the breechblock to strike the'cap of the cartridge. The firing pin is connectedwith a handle 30 which is slidable along the end of the casing 27, thehandle being here shown as threaded to the firing pin.

There is a pin 31 projecting through a slot 32 in the casing 27 and thispin is secured to the firing pin. hen the handle and firing pin aredrawn back to their extreme position a slight turn of the handle willplace the pin 31 in the notch 33 to hold the firing pin in firingposition or cocked. A coiled spring 34 surrounding the firing pin andcompressed between the fixed pin 35 and the locking pin 31 serves tooperate the firing pin. The breech block may restron the seat 36 whendown and I deem it unnecessary to provide any lock for the breech block,although one may be used if desired.

I have shown a simple form of ejector for the cartridges. This comprisespins 37 arranged eccentrically on the trunnions 25 and the pins engagein grooves 38 in parallel rods 39 which slide in the breech 6. Theserods 39 carry at their rear end an ejecting bar 40 which sets in arecess 41 at the back of the breech, part of the cartridge flange-recess 21 being formed in this ejector bar.

The range of the gun is changed by modifying I the action of theexplosive charge upon the projectile and for this purpose I haveprovided a simple device for retaining the projectile at any desiredposition in the barrel until the cartridge is fired. At the underside ofthe breech is shown a rod 44 slidable in a bore 43, and it is adapted tobe projected at various distances into the projectile chamber or bore 45of the gun barrel. This rod 44 is connected by a cross piece 46 with arod 47 which latter is ariunged outside and preferably to one side ofthe barrel, and slidable in a bracket 48. The rods 4-4, 47 are adaptedto be clamped in various positions by means of an eccentric bolt,operated by a handle 49. The forward end of the rod 47 carries anindicator or pointer 50 which cooperates with a scale 51 attached to theside of-the'barrel. The scale 51 is marked to indicate yards, meters, orany other units of measurement.

Operation: The gun having been properly set up at the desired angle, thehandle 49 is turned to release the rods 44, 47 and the latter are movedup or down to bring the pointer 50 to the position 011 thewscale 51where the desired range is indicated, which may be, say, fifty meters.The-handle 49 is then turned "to lock the rods 44, 47 in place and theseparts will remain in this condition so long as the firing is to be atthis same range.

The gunner grasps the handle 30 and swings up the breech block 22, andhe will then place the blank cartridge in the cartridge socket 20 andthen lower the breech block. The projectile is theninserted into themuzzle of the gun and it slides down until it rests upon the upper endof the rod 44 where it remains until expelled by the force of theexplosive.

If the firing pin has'not previously been cocked, the handle 30 is drawnback, thus drawing back the firing pin 28 and com pressing the mainspring 34, and finally the handle 30 is turnedv to enter the pin 31 inthe notch 33. '-To fire the gun it is only necessary to release the pin'31 from the recess 33 and the main spring will project the firing pinagainst the cap of the cartridge, and the cartridge will be thusdischarged.

The distance the projectile will be fired will depend upon its positionin the barrel at the time of the explosion of the cartridge, asdetermined by the supporting rod 44 and as indicated by the pointer 50on the scale 51.

The more the rod 44 is withdrawn, the nearer the projectile will be tothe breech of the gun and vice versa. The nearer to the breech of thebarrel the projectile is held, the greater distance will it be propelledby the explosive and vice versa, provided, of course, that a uniformcharge of explosive is always used.

The nearer to the breech the projectile is supported the greater theeffect of the explosive charge upon it and, consequently, the greaterthe distance it will be projected. On the other hand, the nearer theprojectile is to the muzzlethe shorter will be the range because theexplosive charge will have a space in which to expand behind theprojectile and, consequently, its action on the projectile will be muchweaker. I have found that quite accurate results may be obtained in atrench gun by thus modifying the effect of the explosive on theprojectile. As the barrel of the gu may be retained at the same anglefor various ranges the projectiles when fired at different ranges willtravel in parabolic curves more or less similar and the projectiles willrise high enou h to pass over the ordinary parapet and escend in thetrench.

Having described my invention, what I claim is:

1. A trench gun having means for holding the body of a projectile atvarious positions within its barrel.

2. A trench gun having adjustable means for holding the body of aprojectile at various positions within its barrel.

3. A- trench gun having a barrel and means along the barrel adapted tobe adjusted to hold the projectile at various points with relation tothe barrel.

4:. A trench gun having a bar-rel adapted to receive a projectile ofless diameter than the barrel and fitting within and wholly inclosed bythe latter, the said barrel being normally imperforate, said gun havingmeans for receiving a fixed or standard firing charge, and means formodifying the effect of such fixed or standard firing charge on theprojectile to vary the range of fire without altering the imperforatecharacter of the barrel and independently of the elevation of the gun.

5. A trench gun having a barrel adapted to receive a projectile of lessdiameter than the barrel, and fitting within and Wholly inclosed by thelatter, means for holding a firing charge, and means for varying thespace between the firing charge and projectile to vary the range offire.

6. A trench gun having a barrel, and means movable along the inside ofthe barrel adapted to engage the projectile and hold it in varyingpositions.

7. A trench gun having a barrel, and a rod movable along the inside ofthe barrel adapted to engage the projectile and hold it in varyinpositions.

8. A trench gun having a cartridge chamber, a barrel of larger diameterthan the cartridge chamber, said barrel adapted to bodily receive aprojectile, and means for engaging the projectile at varyingpoints inthe length of the barrel to hold the projectile at varying distancesfrom the cartridge chamber.

9. A trench gun having an explosion chamber, in which the firing chargeis exploded, a barrel of greater diameter than the projectile to befired and adapted to receive the body of the projectile, and means forholding the projectile within the barrel with means for varying thedistance between the explosion chamber and the projectile whereby tovary the range of fire.

10. A gun of the class described including a barrel from which aprojectile is adapted to be fired, said gun having a cartridge chamber,and said barrel having a bore for the projectiles of larger diameterthan the cartridge chamber, and means movable in said bore and adaptedto support the projectiles at different positions in the bore, for thepurpose set forth.

11. A gun of the class described including a barrel from which aprojectile is adapted to be fired, means for holding an explosive chargefor the projectile, and means for modifying the action of the explosiveon the projectiles to vary the range, comprising a rod movable in thebore of the barrel for supporting the projectile at different positionstherein, a rod movable with said first rod and arranged along theoutside of the barrel, and means for indicating the positions of saidrods.

12. Apparatus for firing projectiles com prising a projectile-receivingchamber, and means for positively positioning the proj ectile in saidchamber to vary the size of the expansion space at the rear of theprojectile and to vary the length of the chamber in advance of theprojectile.

13. Apparatus for firing projectiles comprising a projectile-receivingchamber, and means comprising stop mechanism for positively positioningthe projectile in said chamber to vary the size of the expansion spaceat the rear of the projectile and the length of the chamber in advanceof the projectile.

14:. Apparatus for firing projectiles comprising a projectile-receivingchamber, and means independent of the projectile to indicate a pluralityof different positions which the projectile is capable of assuming insaid chamber.

15. Apparatus for firing projectiles comprising a firing chamber, andmeans inde pendent of the projectile for positioning the same to varythe size of the chamber.

. Signed at the city, county and State of New York, this 7th day ofSeptember, 1915.

AXEL G. BERGMAN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. 0.

